1. How the volumes of zazu extraction in Ukraine changed during the years of independence. “Word and Deed”, Analytical portal (2021). https://www.slovoidilo.ua/2021/02/05/infografika/ekonomika/yak-zminyuvalysya-obyemy-vydobuvannya-hazu-ukrayini-roky-nezalezhnosti
2. Gas in Ukraine: import, production, price for the population. Analytical portal “Word and Deed” (2020). [ukr], https://www.slovoidilo.ua/2020/04/28/infografika/ekonomika/haz-ukrayini-import-vydobutok-czina-naselennya/
3. Gas production in Ukraine decreased by 2%-to 19.8 billion cubic meters. EXPRO CONSULTING (2022). [ukr], https://expro.com.ua/novini/vidobuTok-gazu-v-ukran-znizivsya-na-2-do-198-mlrd-kub-m/
4. Gas consumption in Ukraine decreased by 7% during the year-GTS Operator. Economic truth (2022). [ukr], https://www.epravda.com.ua/news/2022/01/14/681457/
5. Soufera, E., Zaborski, S.O.:Biomass as a source of energy, M: Mir, p. 368 (rus) (1985)